（1）Absolute synonyms (complete synonyms) are words which are identical in meaning in all its aspects. i.e. both in grammatical meaning , including conceptual and associative meanings. Synonyms of this type are interchangeable in every way. Absolute synonyms are rare in natural languages and restricted to highly specialized vocabulary, such as scarlet-fever/scarlatina in medicine.
（2）Relative synonyms (near-synonyms) are similar or nearly the same in denotation, but embrace different shades of meaning or different degrees of a given quality. For example, to change a thing is to put another thing in its place; to alter a thing is to make it different from which it was before.
（1）绝对同义词（完全同义词）是指在各方面含义相同的词。也就是说，在语法意义上，包括概念意义和联想意义。这种类型的同义词在各个方面都可以互换。绝对同义词在自然语言中很少见，仅限于高度专业化的词汇，如医学上的猩红热/斯卡拉丁病。
（2）相对同义词（近同义词）在表示上相似或几乎相同，但具有不同的含义或给定性质的不同程度。例如，更换（替换）一件事就是把另一件事放在它的位置上；更改一件事就是使它与以前不同。
